Typs NPM | npm.io

typs

An handy library for type validation in Javascript

Just

npm install typs --save

it.

The library is still widely open to changes, so feel free to propose new features or open an issue.

What can I use it for?

Param checking

Write a sound REST API or provide strong code constraints validating your parameters

app.get('/api/v1/users/:user_id', (req) => {
	var user_id = req.params.user_id;
	if(typs(user_id).integer().positive().notZero()) {
		throw new Error('user_id is not a valid identifier');
	}
	// ...
});

Input validation

Let typs handle your validation logic in an easy and semantic way

const usernameType = typs().string().notEmpty().len({min: 5, max: 15});
const uniqueUsernameType = usernameType.satisifies((username) =>
	// yes, typs supports promises!
	query('SELECT * FROM users WHERE username = ?', username)
		.then((rows) => rows.length < 1);
);
const passwordType = typs().string().notEmpty().len({min: 8, max: 25});
const emailType = typs().string().notEmpty().regex(/* ...a long mail regex... */);

function add_user(username, password, email) {
	if(typs(username).isnt(usernameType)) {
		throw new Error('the username you provided is not a valid username')
	}
	if(typs(password).isnt(passwordType)) {
		throw new Error('the password you provided is not valid');
	}
	if(typs(email).isnt(emailType)) {
		throw new Error('the e-mail you provided is not valid');
	}

	typs(username).isnt(uniqueUsernameType).then((pass) => {
		if (!pass) throw new Error('this username already exists, please pick another');
		// ...
	});
}